G4 PICT OBI AL PRAGTIGAL VE GET ABIE GEOWIXG. 



remained stunted. They yielded very poor crops, and it was notice- 

 able that the seed tubers remained almost unchanged throughout the 

 season. The same state of affairs was observable in 1901. Such a 

 generally reliable variety as Beauty of Hebron was one of the worst 

 affected. Premature ripening of the seed, owing to the hot. dry 

 summers of 1899 and 1900 was suggested as the cause, not without 

 reason, probably. I think, however, that the cold, late springs were 

 contributory, and I am strengthened in this opinion by the fact that 

 in one of my plots that was badly affected a piece of Up-to-Date 

 planted very late (the end of May) was perfectly healthy. If growers 

 have good seed they need be in no hurry to plant in exposed places. 



FIG. 38. -TWITCH IN POTATOES. 



Here is a curious instance of what t^itcli or couch. Triticum repens, 

 will do if not cleared out of Potato ground before planting. It 

 has gone right through the Potato. 



Scah.—l do not know if Potato scab has been exhaustively 

 studied by micro-fungologists. When it does engage their attention, 

 I shall not be surprised to hear that there are several distinct forms. 

 One form of scab is directly due to excess of rank manure. Another 

 (or it may be the same) is just as certainly due to contact with 

 coarse, sharp particles, such as coal ashes or rough stones. AVhere 

 scab is persistently troublesome in the absence of these conditions a 

 little sulphur should be dusted in the drills, or the seed should be 

 soaked in a solution of corrosive sublimate, 1 oz. to 15 gallons of 

 water. Care should be exercised, as the sublimate is a dangerous 

 poison. 



